MediumGHSA-r8hm-w5f7-wj39CVE-2024-21910PYSEC-2026-632

Cross-site scripting vulnerability in TinyMCE plugins

Published 2 Nov 2021 · Updated 8 Jul 2026

Affected packages

tinymcenpm
Affected
<5.10.0
Fixed in
5.10.0
Update to the fixed version for your release line, for example:npm install tinymce@5.10.0
tinymce/tinymceComposer
Affected
<5.10.0
Fixed in
5.10.0
Update to the fixed version for your release line, for example:composer require tinymce/tinymce:^5.10.0

Details

Impact

A cross-site scripting (XSS) vulnerability was discovered in the URL processing logic of the image and link plugins. The vulnerability allowed arbitrary JavaScript execution when updating an image or link using a specially crafted URL. This issue only impacted users while editing and the dangerous URLs were stripped in any content extracted from the editor. This impacts all users who are using TinyMCE 5.9.2 or lower.

Patches

This vulnerability has been patched in TinyMCE 5.10.0 by improved sanitization logic when updating URLs in the relevant plugins.

Workarounds

To work around this vulnerability, either:

  • Upgrade to TinyMCE 5.10.0 or higher
  • Disable the image and link plugins

Acknowledgements

Tiny Technologies would like to thank Yakir6 for discovering this vulnerability.

References

https://www.tiny.cloud/docs/release-notes/release-notes510/#securityfixes

For more information

If you have any questions or comments about this advisory:

  • Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)
  • Open an issue in the TinyMCE repo

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.